JPH0363632B2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to improvements in seismic isolation structures.

As an earthquake-resistant structure for a building structure, there is a seismic isolation structure that not only enhances the seismic strength of the structure but also reduces the seismic energy transmitted from the ground to the structure, and reduces the so-called vibration response amount.

Various types of seismic isolation structures have been proposed in the past, but very few have been put into practical use due to their reliability or economy, and there have been very few examples of them being used for large structures, as shown in Figure 1. The seismic isolation structure shown in the figure is a combination of a laminated rubber 1 and a friction mechanism 2, in which the laminated rubber 1 is interposed between an upper structure 3 and a foundation 4, It is composed of a flat steel plate 5 and a flat rubber 6, which are stacked so that the rubber 6 is sandwiched between the steel plates 5.

On the other hand, the friction mechanism 2 includes a convex portion 7 formed on a part of the base 4 that protrudes upward, and a pair of flat plates having a large friction coefficient between the upper surface of the convex portion 7 and the lower surface of the upper structure 3. 8 are placed facing each other.

In the seismic isolation structure with this configuration, when the foundation 4 moves horizontally due to an earthquake force, the upper structure 3 remains in its original position due to the elastic force and inertia force of the laminated rubber 1. does not move against

In this case, the friction mechanism 2 counteracts the frictional force of the flat plate 8 against large deformations in the horizontal direction, and prevents the laminated rubber 1 from being deformed beyond its elastic limit and losing its function. It had a protective effect and ensured the safety of the seismic isolation structure.

However, the above-mentioned seismic isolation structure had the following problems.

That is, the seismic force applied to the foundation 4 includes not only horizontal movement but also vertical movement.

For this reason, the friction mechanism 2 that protects the laminated rubber 1 does not work effectively, and a force exceeding the elastic limit is applied to the laminated rubber 1, and there is a high possibility that it will be destroyed.

In other words, when vertical motion is applied to the foundation 4, the friction mechanism 2
The flat plates 8 arranged facing each other are separated, and the frictional force generated by contacting each other is almost eliminated, and the protective function of the laminated rubber 1 is lost, causing the laminated rubber 1 to undergo shear failure. Become.

This invention was made in view of the problems of conventional seismic isolation structures as described above, and its purpose is to create a seismic isolation structure that is less likely to be destroyed by horizontal or vertical motion. It's there to provide.

In order to achieve the above object, the present invention provides a base isolation structure that is interposed between an upper structure and a lower structure to absorb vibration transmitted between these structures. It is characterized by consisting of a plurality of metal cylinders arranged in the radial direction with a distance between them, and particles made of a polymeric material filled between these cylinders.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 2 to 4 show an embodiment of the seismic isolation structure according to the present invention.

The seismic isolation structure shown in the figure includes a plurality of cylindrical bodies 10, 10, which are open at both ends, arranged concentrically in the radial direction at approximately equal intervals, and the cylindrical bodies 10, 1.
0... It is composed of a granular material 12 made of a polymeric material filled between relatively large upper structures 14 such as building structures, reactor vessels, tanks, etc., and lower structures such as their foundations. A suitable number of the structures are interposed between the structures 14 and 16 to absorb vibrations transmitted between the structures 14 and 16.

The cylindrical bodies 10, 10, . The following settings are made, and the number and location of the upper structure 14 are determined in consideration of the weight, shape, etc. of the upper structure 14.

The granules 12 are made of a polymeric material such as synthetic rubber, synthetic resin, or a mixture of ferrite and synthetic resin, and are formed into a substantially spherical shape, so that they can resist external forces applied from any direction. At the same time, when filling between the cylinders 10, 10..., it is preferable to perform compression filling.

The upper and lower open ends of the cylindrical bodies 10, 10, .
16 by appropriate means.

In the seismic isolation structure having the above-described configuration, when a vertical seismic force acts on the lower structure 16, the cylindrical bodies 10, 10... are bent so as to expand or contract their diameters. , the inside is filled with granules 12, which are made of polymer material, and each granule 12 is connected vertically in a chain shape, so the seismic force is absorbed by each granule 12 and the upper part Since it is transmitted to the structure 14, the amount of transmission can be significantly reduced.

On the other hand, when a horizontal seismic force acts on the lower structure 16, the cylindrical bodies 10, 10...
The cross-sectional shape of the upper structure 14 is bent and deformed due to the inertial force of the upper structure 14, but in this case, each cylinder 1
0, 10... Particles 12 made of polymeric material between
, each of which deforms elastically and absorbs horizontal motion. This allows the horizontal seismic force transmitted to the superstructure 14 to be significantly reduced.

What should be particularly noted here is that in addition to the above effects, the following effects are also achieved.

That is, the seismic isolation structure of the present invention is composed of a metal cylindrical body 10 and a granular material 12 made of a polymeric material filled inside the metal cylinder body, so that the drawbacks of these materials can be compensated for. .

In other words, although the elastic limit of metal materials is generally not large, in this invention, when an earthquake force is applied from the outside, the internal granules are 12 absorbs earthquake forces and prevents destruction.

In addition, on the contrary, polymer materials usually have a large elastic limit, but do not have the strength to support the large weight of building structures, etc.
0... complements.

Therefore, in the seismic isolation structure of the present invention, the deformability against external forces approaches that of an elastic body, and it also has a restoring force when the external forces are released.

FIG. 5 shows another embodiment of the present invention, and only its characteristic parts will be described below.

The seismic isolation structure shown in the figure includes the cylindrical bodies 10, 10...
... and the end plates 18, 18, one of the cylinders 10 is not fixed to the end plate 18 and is made into a free end 10a, and in the same figure, the free end 10a is alternately It is configured so that

With this configuration, the seismic force transmitted from the lower structure 16 to the upper structure 14 can be reduced.
This means that the granules 12 can absorb it even more effectively.

Furthermore, a so-called elasto-plastic material may be interposed in the free end 10a, for example, by increasing the carbon content of hard rubber and having plasticity in addition to the elasticity that rubber originally has.

In the above embodiment, the cylindrical body 10 is illustrated, but it is of course possible to make the body 10 oval or square.

Further, the end plate 18 can be fixed to the upper or lower structures 14, 16 not only by directly fixing it, but also by interposing a vibration absorbing plate made of hard rubber or the like between them.

As explained above in the embodiments, the seismic isolation structure according to the present invention is composed of a plurality of metal cylindrical bodies and granular material made of polymer material filled between the cylindrical bodies, so that it resists horizontal or vertical motion. It is less likely to be destroyed by effective countermeasures.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a conventional seismic isolation structure. Second
Figures 4 to 4 show an embodiment of the base isolation structure of the present invention. Figure 2 is an overall explanatory diagram, Figure 3 is a cross-sectional view taken along the line -2 in Figure 2, and Figure 4 is a cross-sectional view of the base isolation structure of the present invention. Figure -
FIG. FIG. 5 is a sectional view of a main part showing another embodiment of the present invention. 1...Laminated rubber, 2...Friction mechanism, 3...Superstructure, 4...Foundation, 5...Steel plate, 6...Rubber, 7
... Convex portion, 8 ... Flat plate, 10 ... Cylindrical body, 12 ...
Granular material, 14... Upper structure, 16... Lower structure, 18... End plate.

Claims (1)

[Claims] 1. In a seismic isolation structure that is interposed between an upper structure and a lower structure to absorb vibrations transmitted between these structures, this seismic isolation structure consists of structures arranged in the radial direction at intervals. A seismic isolation structure characterized by comprising a plurality of metal cylinders and particles made of a polymeric material filled between these cylinders.